The Research Of High Sensitivity Hydrophone

High sensitivity hydrophones can detect much smaller signal and produce larger response than the hydrophones that have lower sensitivity.Since the area of the lids exposed to water is much greater than the area of the PZTs, the pressure on the PZT is also much greater than the pressure on the lid. This will observably increase the sensitivity of hydrophones. Based on this effect two kinds pressure hydrophones of high-sensitivity were designed in this paper: Tonpilz design and MiniCan design. In the beginning of this paper gives sensitivity of the sound pressure hydrophone that has lids, analyses the main factors that influence sensitivity of pressure hydrophone and then gives the structures of the Tonpilz design and the MiniCan design.Then, by using ANSYS finite element software this paper optimize the design of Tonpilz and MiniCan. And the influence of the size of structure of the hydrophone on resonance frequency and sensitivity was researched and the resistance characteristics and sensitivity of these two hydrophones in the air and water is also calculated. It is found, that operating upper limit of bandwidth of the optimized Tonpilz design is 15 kHz, pressure sensitivity is -189dB, band fluctuations is less than 3dB. And the operating upper limit of bandwidth of the optimized the MiniCan design is 20 kHz, its pressure sensitivity is -176dB, its band fluctuations is less than 3dB.In the last step, a Tonpilz design and a MiniCan design were produced, and their resistance characteristics and sensitivity will be measured in the water. The tests show that this type of hydrophone have much higher sensitivity, this tested results is basically consistent with the calculated results of ANSYS software.